TrolMaster OM-8 Dry Contact Board | Eight Outputs at 12 A Each

Eight Contacts on the TrolMaster OM-8, and What They Carry

Eight individual contacts sit on this board and each one is rated to twelve amps. That is the number that decides where it belongs. Plug-in device stations around this range handle a single load each and top out lower. A room with eight separate pumps or valves either collects a wall of stations, or uses one board. Overload protection sits on each of the eight outputs rather than shared across the board. One faulty load therefore does not take the other seven with it. An LCD on the board shows what is happening. Each contact can also be forced open or closed manually for thirty minutes. That is how commissioning and fault finding get done without unplugging anything. That thirty minute limit is deliberate and it means a forced contact returns to automatic control on its own. On an Aqua-X Pro system this is the part that drives pumps and solenoids at twelve amps rather than at a station rating. One sixteen foot RJ12 cable comes in the box.

Mounting It in a Control Cabinet and the Heat Limit

This is not a plug-in box and it is not meant to hang on a wall. TrolMaster specify mounting inside an electrical enclosure, wired to a supply between a hundred and two hundred and forty volts AC. That puts installation with an electrician and it puts the board behind a door rather than in the open. One number deserves more attention than it usually gets. The working temperature limit is 104 F, which is lower than most of the range and lower than people assume. A closed cabinet holding contactors, drivers and a transformer runs warm, and a cabinet in a plant room in summer runs warmer still. Check the internal temperature of the enclosure rather than the room, and fit a vent or a fan if it sits near the limit. Humidity is capped at ninety percent. The board measures 255 by 135 by 95 mm packed. Label the eight contacts at installation, because working out which is which later costs far more time than writing them down now.

Key Features

• Contacts: Eight independent electrical contacts on a single board
• Rating: Up to twelve amps through each contact
• Protection: Overload protection on each output rather than shared
• Display: An LCD on the board shows the current state
• Manual override: Any contact can be forced open or closed for thirty minutes
• Auto return: A forced contact reverts to automatic control by itself
• Aqua-X Pro: Lets pumps and solenoids run at the higher twelve amp rating
• Mounting: Inside an electrical enclosure, not on an open wall
• Supply: Wired to a hundred to two hundred and forty volts AC
• Heat limit: Working range stops at 104 F, so cabinet temperature matters

Technical Specifications